Reviews claiming dramatic weight loss without mentioning caloric restriction are either conflating correlation with causation or are not disclosing other interventions
I bought some methylcobalamin from Oxford Biosciences a couple of years ago - and ended up not using it because I was concerned about storage and maintaining the sterile status of the injectable B12
Semaglutide use: Semaglutide itself slows gastric emptying, which may indirectly impair your bodys ability to absorb vitamin B12, leading to a vitamin B12 deficiency
At a separate -arrestin recruitment pathway at GLP-1R, reta E_max = 40% of native (partial / biased agonism), tirzepatide partial in the same direction, semaglutide full at both pathways
Quick response and delivery
A systematic review of 35 prospective cohort studies assessing the association between vitamin B 12 status and cognitive deterioration in older individuals with or without dementia at baseline did not support a relationship between serum vitamin B 12 concentrations and cognitive decline, dementia, or Alzheimers disease (79)